Rail tie pad

ABSTRACT

A rail tie pad for use with a cast rail tie. The rail tie pad may be flexible, polymeric body having first and second opposite sides and, when viewed in cross-section, includes an upper surface and a lower surface defining a first vertical thickness and including a plurality of undulations with alternating concave portions and convex portions. The rail tie pad further includes a pair of side anchor portions respectively disposed at the first and second opposite sides of the pad, each including at least one anchor projection for embedment within the side portions of a cast rail tie. In this manner, the anchor portions of the rail tie pad are embedded within, and fixably secure, the sides of the rail tie pad to the cast rail tie to mitigate or prevent separation of the rail tie pad from the rail tie during transport and/or positioning of the rail tie during installation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under Title 35, U.S.C. § 119(e) ofU.S. Provisional Patent Application Ser. No. 62/743,848, entitled RAILTIE PAD, filed on Oct. 10, 2018, the disclosure of which is expresslyincorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates to rail tie pads of the type used tosupport rail ties in a railway system and, in particular, relates to arail tie pad including a flexible, polymeric body which is joined to acast rail tie for supporting the rail tie in a rail bed and forattenuating vibrations from passing engines and railcars.

2. Description of the Related Art

In a railway system, rails are supported by a large number of rail tiesor sleepers, which are supported in a rail bed that is formed of aballast such as aggregate material. The ballast may be supported on abed of sub-ballast, which in turn may be supported on a formation,subgrade, and/or foundation. Passing train engines and railcars causevibrations throughout the rails and the rail ties which are transferredthrough such components to the ballast and other support grades. Toattenuate the vibrations and provide an extended service life of therails and rail ties, rail tie pads are provided to support the rail tieswithin the ballast, and are typically made of a flexible, polymericmaterial.

The rail tie pads may be positioned or seated between the rail ties andthe ballast without any physical connection between the rail ties andthe rail tie pads, or the rail tie pads may be joined to the rail tiesvia an adhesive, for example. In other configurations, the rail ties areformed of a cast material, such as concrete or a composite material, andthe rail tie pads are integrally joined to the cast rail ties by theembedment of anchoring features of the rail tie pads within the castmaterial of the rail ties at the time of casting the rail ties.

When using rail pads that are joined to the rail ties, either viaadhesive or partial embedment of the rail tie pads within the cast railties, problems may occur based on partial or complete separation of therail tie pads from the rail ties prior to installation of the rail tieswithin the ballast during assembly of the railway system and/or duringrepair or replacement of rail ties within an existing railway system.For example, when rail ties are moved using a forklift, the ends of thefork tines of the forklift may contact the rail tie pads and strip themaway from their associated rail ties and/or may lodge between the railtie pads and the rail ties and separate or dislodge the rail tie padsfrom the rail ties.

What is needed is an improvement over the foregoing.

SUMMARY

The present disclosure provides a rail tie pad for use with a cast railtie. The rail tie pad may be flexible, polymeric body having first andsecond opposite sides and, when viewed in cross-section, includes anupper surface and a lower surface defining a first vertical thicknessand including a plurality of undulations with alternating concaveportions and convex portions. The rail tie pad further includes a pairof side anchor portions respectively disposed at the first and secondopposite sides of the pad, each including at least one anchor projectionfor embedment within the side portions of a cast rail tie. In thismanner, the anchor portions of the rail tie pad are embedded within, andfixably secure, the sides of the rail tie pad to the cast rail tie tomitigate or prevent separation of the rail tie pad from the rail tieduring transport and/or positioning of the rail tie during installation.

In one form thereof, the present disclosure provides a rail tie pad foruse with a cast rail tie, including a flexible, polymeric body havingfirst and second opposite sides and including, when viewed incross-section: an upper surface and a lower surface defining a firstvertical thickness therebetween, and each including a plurality ofundulations with alternating concave portions and convex portions; and apair of side anchor portions respectively disposed at the first andsecond opposite sides of the pad, the side anchor portions each having asecond vertical thickness greater than the first vertical thickness,each side anchor portion extending upwardly from the upper surface andincluding at least one anchor projection for embedment within a castrail tie.

The concave portions of the undulations of the upper surface may bevertically aligned with the convex portions of the undulations of thelower surface, and the convex portions of the undulations of the uppersurface may be vertically aligned with the concave portions of theundulations of the lower surface.

The side anchor portions may each extend substantially entirely alongthe first and second opposite sides of the pad. The rail tie pad mayfurther include at least one central anchor portion disposed between thepair of side anchor portions, each central anchor portion having a thirdvertical thickness greater than the first vertical thickness andextending upwardly from the upper surface, each central anchor portionfurther including at least one anchor projection for embedment within acast rail tie.

The side anchor portions may each have a substantially triangularprofile when viewed in cross-section, and also may include verticaloutermost walls which, when the rail tie pad is cast within a cast railtie, are disposed substantially vertically flush with side walls of thecast rail tie. When viewed in cross-section, the vertical outermostwalls of the side anchor portions may each be joined to the lowersurface of the rail tie pad via a rounded corner. The anchor projectionsof the side anchor portions may each extend at an angle with respect tothe top surface of the rail tie pad.

The polymeric body may be made of an elastomer having a hardness between50 Shore A and 80 Shore A.

In another form thereof, the present disclosure provides a cast railtie, including a cast tie body including a top side, a bottom side, anda plurality of side walls; and a rail tie pad joined to the bottom sideof the cast body, the rail tie pad including a flexible, polymeric bodyhaving first and second opposite sides and, when viewed incross-section, an upper surface and a lower surface defining a firstvertical thickness therebetween, the rail tie pad further including apair of side anchor portions respectively disposed at the first andsecond opposite sides of the pad, each side anchor portion including atleast one anchor projection adapted for embedment within a cast railtie.

The side anchor portions may extend substantially entirely along thefirst and second opposite sides of the rail tie pad, and/or may eachextend upwardly from the upper surface and have a second verticalthickness greater than the first vertical thickness. The side anchorportions of the rail tie pad may each include vertical outermost wallswhich are disposed substantially vertically flush with respective sidewalls of the cast tie body. The side anchor portions of the rail tiepad, when viewed in cross section, may extend vertically upwardly beyondthe bottom side of the cast tie body.

When viewed in cross-section, the vertical outermost walls of the sideanchor portions of the rail tie pad may each be joined to the lowersurface of the rail tie pad via a rounded corner. The anchor projectionsof the side anchor portions may extend at an angle with respect to thetop surface of the rail tie pad.

The upper surface and the lower surface of the rail tie pad may eachinclude a plurality of undulations with alternating concave portions andconvex portions. The concave portions of the undulations of the uppersurface may be vertically aligned with the convex portions of theundulations of the lower surface of the rail tie pad, and the convexportions of the undulations of the upper surface may be verticallyaligned with the concave portions of the undulations of the lowersurface of the rail tie pad.

The rail tie pad may further include at least one central anchor portiondisposed between the pair of side anchor portions, each central anchorportion having a third vertical thickness greater than the firstvertical thickness and extending upwardly from the upper surface, eachcentral anchor portion further including at least one anchor projectionembedded within the cast tie body.

The material of the cast tie body may entirely fill each of the concaveportions of the undulations of the upper surface of the rail tie pad.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a portion of an exemplary railway system;

FIG. 2 is a perspective view of a rail tie pad in accordance with thepresent disclosure;

FIG. 3 is a sectional view taken along line 3-3, the rail tie pad ofFIG. 2;

FIG. 4 is a partial sectional view of a portion of the rail tie pad ofFIG. 3, showing same embedded within a cast rail tie;

FIG. 5 is a sectional view showing a cast rail tie and rail tie pad ofFIGS. 2-4 positioned in a rail bed;

FIG. 6 is a partial sectional view of a portion of the rail tie pad ofFIGS. 2-4 according to an alternate embodiment;

FIG. 7 is a sectional view of a rail tie pad according to an alternateembodiment;

FIG. 8 is a partial sectional view of a portion of the rail tie pad ofFIG. 7, showing same embedded within a cast rail tie;

FIG. 9 is a sectional view showing a cast rail tie and rail tie pad ofFIGS. 6 and 7 positioned in a rail bed;

FIG. 10 is a sectional view of a rail tie pad according to an alternateembodiment;

FIG. 11 is a partial sectional view of a portion of the rail tie pad ofFIG. 10, showing same embedded within a cast rail tie;

FIG. 12 is a sectional view showing a cast rail tie and rail tie pad ofFIGS. 10 and 11 positioned in a rail bed; and

FIG. 13 is a sectional view showing a rail tie pad according to analternate embodiment embedded within a cast rail tie.

DETAILED DESCRIPTION

Referring to FIG. 1, a portion of an exemplary railway system 10 isshown, including rails 12 supported by a suitable rail fastening system14 on rail ties 16 which are in turn supported within a rail bed 18 ofaggregate, concrete, or other material. The rail ties 16 are made of acast material such as concrete or a composite material, for example, andas discussed further below, each rail tie 14 includes a rail tie pad 20in accordance with the present disclosure which is joined to the railtie 16. Each rail tie 16 includes a top side 22 to which the rails 12are joined via the fail fastening system 14, an opposite bottom side(unnumbered) to which the rail tie pad 20 is joined in the mannerdiscussed below, and a plurality of substantially vertical side walls26.

Referring to FIG. 2, a rail tie pad 20 is shown in accordance with afirst embodiment, which generally includes a flexible, polymeric bodymade of a rubber of elastomeric material, for example. The material ofrail tie pad may have a hardness of as little as 40, 50 or 60 Shore A,or as great as 70, 80, or 90 Shore A, or a hardness within any rangedefined between any two of the foregoing values, such as from 40 to 90Shore A, from 50 to 80 Shore A, or from 60 to 70 Shore A, for example.

The rail tie pad 20 includes, with further reference to FIGS. 3 and 4,an upper surface 30 and a lower surface 32, as well as a first andsecond sides 34 and 36 and, referring back to FIG. 2, first and secondends 38 and 40. The rail tie pad 20 may be made according to anextrusion-based method in which an elongate extrusion having the profileshown in cross-section in FIGS. 2 and 3 is cut to a desired length toform ends 38 and 40 of rail tie pad 20.

Referring to FIGS. 3 and 4, upper surface 30 and lower surface 32 eachinclude a plurality of undulations with alternating concave portions 42and convex portions 44. As shown, the concave portions 42 of theundulations of the upper surface 30 are vertically aligned with convexportions 44 of the undulations of the lower surface, and the convexportions 44 of undulations of the upper surface 30 are verticallyaligned with the concave portions 42 of undulations of the lower surface32.

Referring to FIG. 4, a vertical thickness T₁ is defined as the verticaldistance between a convex portion 44 in an undulation of the uppersurface 30 and a convex portion 44 of an undulation of the lower surface32. A vertical thickness T₂ is defined as the vertical distance betweeneither a convex portion 44 in an undulation of the upper surface 30 anda horizontally aligned concave portion 42 of an undulation of the lowersurface 32, or the vertical distance between a concave portion 42 in anundulation of the upper surface 30 and a horizontally aligned convexportion 44 of an undulation of the lower surface 32. For the purposes ofthis disclosure, the term “vertical thickness” as used between the uppersurface 30 and the lower surface 32 of the rail tie pad 20 encompasseseither or both of vertical thickness T₁ and T₂.

Referring to FIGS. 2-4, rail tie pad 20 includes a pair of side anchorportions 50 respectfully disposed at the first and second opposite sides34 and 36 of the pad 20 and which, as best shown in the perspective viewof FIG. 2, extend in length substantially entirely along the first andsecond sides 34 and 36. More specifically, with reference to FIG. 4, theside anchor portions 50 each extend upwardly from upper surface 30 ofpad 20 to define a vertical thickness greater than the verticalthickness of pad 20, and are positioned at the terminal or outermostends of the respective first and second opposite sides 34 and 36 sidesof the pad 20 for reasons discussed further below.

Side anchor portions 50 each have a substantially triangular shape orprofile in cross-section, and include a vertical outermost wall 52which, when rail tie pad 20 is cast within a cast rail tie 16 as shownin FIG. 4, are disposed substantially vertically flush with a respectiveside wall 26 of the cast rail tie 16. Referring to FIG. 4, each verticalwall 52 is joined to the lower surface 32 of rail tie pad 20 via arounded corner 54 having a generally large radius in order to aid indeflecting objects, such as forklift tines, for example, that maycontact the side anchor portions 50 of rail tie pad 20 during transportand/or positioning of the rail tie pad 20 during installation. In thismanner, the rounded corners 54 aid in maintaining the integral, fixedconnection between side anchor portions 50 of rail tie pad 20 and thecast rail tie 16.

Side anchor portions 50 also each include at least one anchor projection56 projecting therefrom for embedment within the cast material of thecast rail tie 16. In the embodiment shown in FIGS. 2-4, anchorprojection 56 is T-shaped, including a central stem portion 58 and anarrow-shaped head portion 60. As illustrated in FIG. 4, anchorprojections 56 may be disposed at an angle A₁ with respect to uppersurface 30 of rail tie pad 20, which may be as little as 20, 30, or 40degrees, or as great as 50, 60, or 70 degrees, for example, or may be anangle within any range defined between any two of the forgoing values,such as 20 to 70 degrees, 30 to 60 degrees, or 40 to 50 degrees, forexample. In one embodiment, angle A₁ is 45 degrees.

Advantageously, in the event that a side anchor portion 50 is contactedby an external object in a direction generally perpendicular to itsvertical wall 52, anchor portion 50 will tend to be subjected to adislodgement force which generally in a direction aligned along a 45degree angle with respect to the vertical wall 52, and the positioningof anchor projection 56 at angle A₁ positions anchor portion directly inline with, yet opposed to, the dislodgement force to fully resist thedislodgement force.

Referring to FIGS. 3 and 4, rail tie pad 20 may further include at leastone central anchor portion 62 positioned between side anchor portions50, for example, as shown in FIG. 3, rail tie pad 20 includes a singlecentral anchor portion 62 positioned equidistantly between side anchorportions at the lateral center of rail tie pad 20, with central anchorportion 62 also including an increased thickness with respect to thevertical thickness of rail tie pad 20. Similar to side anchor portions50, central anchor portion 62 also includes a T-shaped anchor projection64 for embedment within the material of cast rail tie 16, and alsoextends upwardly from upper surface 30 of pad 20 to define a verticalthickness greater than the vertical thickness of pad 20.

When rail tie 16 is cast, a cast material, such as concrete, is poured asuitable mold (not shown) or other form structure to form the body ofthe tie 16. Then, when the cast material is still wet and uncured, raidtie pad 20 is placed upside-down on top of the case tie body with uppersurface 30 of pad 20 engaging the cast material, and side anchorportions 50 and central anchor portion 62 pressed into the castmaterial. A vibration device (not shown) is typically used to vibratethe entire form structure, or a portion of the form structure such as aplate positioned over the rail tie pad 20 across the top of the formstructure. The application of vibrations to the cast tie body and railtie pad 20 firmly engages and presses the upper surface 30 of the railtie pad 20 into the cast material, and also fully presses and embeds theside anchor portions 50 and central anchor portion 62 within the castmaterial. In this manner, the cast material completely surrounds andfills the spaces between side and central anchor portions 50 and 62, andcompletely fills concave portions 42 of the undulations of upper surface30 of rail tie pad 20. Upon curing of the cast material, rail tie pad 20will be firmly joined and fixed to the cast tie 16, with the embedmentof side and central anchor portions 50 and 62 within the cast materialof tie 16 providing a robust, integral connection between rail tie pad20 and the bottom side 24 of cast rail tie 16 which is resistant toseparation. Additionally, the filling of the cast material withinconcave portions 42 of the undulations of upper surface 30 of rail tiepad 20 assists with the lateral fixation of rail tie pad 20 to thebottom side 24 of cast rail tie 16.

In another process, rail tie pad 20 may be placed in the bottom of amold or form structure and the cast material poured into the mold orform structure onto rail tie pad 20, followed by optionally applyingvibrations to the cast structure to firmly engage and press the uppersurface 30 of the rail tie pad 20 into the cast material, and also fullypress and embed the side anchor portions 50 and central anchor portion62 within the cast material, as described above.

The rail tie pads disclosed herein need not be formed monolithically ofa single material, but rather may be formed of at least two materials ina dual-durometer configuration. For example, referring to FIG. 6, railtie pad 20 according to FIGS. 2-4 is shown according to an alternateconfiguration in which a first portion 66, shown as a majority portionof pad 20, is formed of a first, relatively soft rubber or elastomericmaterial such as that described above. A second portion 68 of pad 20,shown in FIG. 6 as a minority portion of pad 20, is formed of a secondrubber or elastomeric material, or a plastic material, which isrelatively harder than the material of first portion 66. In theembodiment of FIG. 6, the anchor projections 56 and 64 of anchorportions 50 and 62, respectively, are formed in second portion 68 of therelatively harder material to provide more rigidity to anchorprojections 56 and 64 to further prevent potential pull-out orseparation of rail tie pad 20 from cast rail tie 16.

Referring to FIGS. 7-9, a rail tie pad 70 according to a secondembodiment is shown which, except as described below, is identical torail tie pad 20 of FIGS. 2-4 described above, and the same referencenumerals have been used to designate identical components therebetween.Rail tie pad 70 includes side anchor portions 50 having anchorprojections 72 formed as inverted undercut, or dovetail-shaped,projections, as well as three central anchor portions 62 with anchorprojections 74 of the same shape as anchor projections 72, with centralanchor portions 62 relatively evenly spaced with respect to one anotheralong the horizontal extent of rail tie pad 70.

Referring to FIGS. 10-12, a rail tie pad 80 according to a thirdembodiment is shown which, except as described below, is identical torail tie pads 20 and 70 of FIGS. 2-4 described above, and the samereference numerals have been used to designate identical componentstherebetween. Rail tie pad 80 includes side anchor portions 50 havinganchor projections 82 having a T-shape though, as shown in FIG. 11, aredisposed at an angle A₂ of approximately 60 degrees with respect toupper surface 30 of rail tie pad 80.

Referring to FIG. 13, a rail tie pad 90 according to a still furtherembodiment is shown which, except as described below, is identical torail tie pad 20 of FIGS. 2-4 described above, and the same referencenumerals have been used to designate identical components therebetween.Side anchor portions 92 of rail tie pad 90 are formed as elongateextensions, including vertical walls 94 which extend along the sidewalls 26 of cast rail tie 16 a distance as little as 1 inch, 2 inches,or 3 inches, or as great as 4 inches, 5 inches, or 6 inches, or withinany range defied between any two of the foregoing values, such as 1 to 6inches, 2 to 5 inches, or 3 to 4 inches, for example.

In this manner, side anchor portions 92 provide a greater overlap withside walls 26 of cast rail tie 16 to enhance the connection between railtie pad 90 and cast rail tie 16 and further aid in deflecting objects,such as forklift tines, for example, that may contact the side anchorportions 92 of rail tie pad 20 along their vertical extent duringtransport and/or positioning of the rail tie pad 90 during installation.

As used herein, the phrase “within any range defined between any two ofthe foregoing values” literally means that any range may be selectedfrom any two of the values listed prior to such phrase regardless ofwhether the values are in the lower part of the listing or in the higherpart of the listing. For example, a pair of values may be selected fromtwo lower values, two higher values, or a lower value and a highervalue.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variancesthat fall within the scope of the appended claims.

What is claimed is:
 1. A rail tie pad for use with a cast rail tie,comprising: a flexible, polymeric body having first and second oppositesides and including, when viewed in cross-section: an upper surface anda lower surface defining a first vertical thickness therebetween, andeach including a plurality of undulations with alternating concaveportions and convex portions; and a pair of side anchor portionsrespectively disposed at the first and second opposite sides of the pad,the side anchor portions each having a second vertical thickness greaterthan the first vertical thickness, each side anchor portion extendingupwardly from the upper surface and including at least one anchorprojection for embedment within a cast rail tie.
 2. The rail tie pad ofclaim 1, wherein the concave portions of the undulations of the uppersurface are vertically aligned with the convex portions of theundulations of the lower surface, and the convex portions of theundulations of the upper surface are vertically aligned with the concaveportions of the undulations of the lower surface.
 3. The rail tie pad ofclaim 1, wherein the side anchor portions each extend substantiallyentirely along the first and second opposite sides of the pad.
 4. Therail tie pad of claim 1, further comprising at least one central anchorportion disposed between the pair of side anchor portions, each centralanchor portion having a third vertical thickness greater than the firstvertical thickness and extending upwardly from the upper surface, eachcentral anchor portion further including at least one anchor projectionfor embedment within a cast rail tie.
 5. The rail tie pad of claim 1,wherein the side anchor portions each have a substantially triangularprofile when viewed in cross-section.
 6. The rail tie pad of claim 1,wherein the side anchor portions include vertical outermost walls which,when the rail tie pad is cast within a cast rail tie, are disposedsubstantially vertically flush with side walls of the cast rail tie. 7.The rail tie pad of claim 6, wherein, when viewed in cross-section, thevertical outermost walls of the side anchor portions are each joined tothe lower surface of the rail tie pad via a rounded corner.
 8. The railtie pad of claim 7, wherein the anchor projections of the side anchorportions each extend at an angle with respect to the top surface of therail tie pad.
 9. The rail tie pad of claim 1, wherein the polymeric bodyis made of an elastomer having a hardness between 50 Shore A and 80Shore A.
 10. A cast rail tie, comprising: a cast tie body including atop side, a bottom side, and a plurality of side walls; and a rail tiepad joined to the bottom side of the cast body, the rail tie padincluding a flexible, polymeric body having first and second oppositesides and, when viewed in cross-section, an upper surface and a lowersurface defining a first vertical thickness therebetween, the rail tiepad further including a pair of side anchor portions respectivelydisposed at the first and second opposite sides of the pad, each sideanchor portion including at least one anchor projection adapted forembedment within a cast rail tie.
 11. The cast rail tie of claim 10,wherein the side anchor portions extend substantially entirely along thefirst and second opposite sides of the rail tie pad.
 12. The cast railtie of claim 10, wherein the side anchor portions of the rail tie padeach extend upwardly from the upper surface and have a second verticalthickness greater than the first vertical thickness.
 13. The cast railtie of claim 10, wherein the side anchor portions of the rail tie padinclude vertical outermost walls which are disposed substantiallyvertically flush with respective side walls of the cast tie body. 14.The cast rail tie of claim 10, wherein the side anchor portions of therail tie pad, when viewed in cross section, extend vertically upwardlybeyond the bottom side of the cast tie body.
 15. The cast rail tie ofclaim 10, wherein, when viewed in cross-section, the vertical outermostwalls of the side anchor portions of the rail tie pad are each joined tothe lower surface of the rail tie pad via a rounded corner.
 16. The castrail tie of claim 10, wherein the anchor projections of the side anchorportions extend at an angle with respect to the top surface of the railtie pad.
 17. The cast rail tie of claim 10, wherein the upper surfaceand the lower surface of the rail tie pad each include a plurality ofundulations with alternating concave portions and convex portions. 18.The cast rail tie of claim 17, wherein the concave portions of theundulations of the upper surface are vertically aligned with the convexportions of the undulations of the lower surface of the rail tie pad,and the convex portions of the undulations of the upper surface arevertically aligned with the concave portions of the undulations of thelower surface of the rail tie pad.
 19. The cast rail tie of claim 10,further comprising at least one central anchor portion disposed betweenthe pair of side anchor portions, each central anchor portion having athird vertical thickness greater than the first vertical thickness andextending upwardly from the upper surface, each central anchor portionfurther including at least one anchor projection embedded within thecast tie body.
 20. The cast rail tie of claim 10, wherein a material ofthe cast tie body entirely fills each of the concave portions of theundulations of the upper surface of the rail tie pad.